1. Field of The Invention
The present invention relates to an electrical card connector for electrically connecting an exterior electrical apparatus to a circuit board, and particularly to an electrical card connector with a multi-stroke ejector means for providing users with a labor-saving function.
2. The Prior Art
As shown in FIG. 1, a prior art electrical card connector 5 includes a housing body 50, a combining means 51 and a mechanical ejector 52 therein wherein the ejector 52 further consists of a pair of opposed guiding bars 521, a metallic pushing plate 522, a lever 523 and an actuator 524. When all of the parts are assembled with each other, the metallic pushing plate 522 is parallel to a horizontal axis of the housing body 50, and the combining means 51 and the lever 523 are successively positioned above the pushing plate 522 in a stacked relationship, and the pair of opposed guiding bars 521 are respectively deposited in opposed and spaced ends of the housing body 50 and one of the bars 521 is further laterally deposited with the actuator 524. In detail, a groove 5231 of the lever 523 is rotatablely attached to a protrusion 5221 bent on the pushing plate 522 to permit that the lever 523 can pivot upon the protrusion 5221 of the pushing plate 522 in a specific angle. A bore 5232 defined on the lever 523 is rotatablely attached to a downward flange 5101 protruded on the combining means 51. A free end of the lever 523 exposed to the outside of housing body 50 (shown in FIG. 2) is further clamped by a fork portion 5241 formed in an end of the actuator 524 of which opposite end forms an operation button 5242. When said operation button 5242 of the actuator 524 is manually pushed by a user, the whole actuator 524 is horizontally moved along one lateral side of the corresponding guiding bar 521 to actuate said free end of the lever 523. Simultaneously, the lever 523 pivots upon the flange 5101 of the combining means 51 which functions as a fulcrum, so that the groove 5231 thereof accompanying the protrusion 5221 of the plate 522 can actuate the whole pushing bar 522 to slide outwardly thereby ejecting an electrical card out which has been inserted into the electrical card connector.
However, prior art electrical card connectors may encounter an undesired problem in a manual operation that a larger operating force for completely ejecting the inserted electrical card out is usually required in an instant, because of an overly short operating force arm F formed between the free end and the bore 5232 of the lever 523 as shown in FIG. 2, even the operating force arm F is longer than an acting force arm R formed between the bore 5232 and the groove 5231 of the lever 523.
The other type of prior art electrical card connectors for resolving the foregoing problem have proposed a labor-saving ejector mechanism, as disclosed in U.S. Pat. Nos. 5,383,789 and 5,421,737, which consists of a curved lever and a pair of curved contact surfaces formed on the housing body in response to the lever. However, some abrupt changes in the curved contours of either the lever or the contact surfaces cause that the structure thereof are too complicated and not easily formed thereby requiring a higher manufacturing cost. In addition, because the designs of the curved contours thereof are asymmetrical and offset from each other, it causes that when the lever respectively pivots upon the contact surfaces in different radians, the ejecting steps such as drawing the electrical card drawn from the connection with the contacts of the connector or completely ejecting the electrical card out may be not completely executed. And, due to the curved contours of both of the lever and the corresponding contact surfaces being asymmetrical with each other, a "die point" in the structures may exist to delay the ejecting time of the electrical card in the operation process thereof.
Accordingly, to resolve the above problems, an object of the present invention is to provide an electrical card connector of which multi-stroke ejector means includes a lever and a pair of supporting surfaces symmetrically formed on a housing body of the connector for providing the lever with a variable fulcrum to constitute different force arms for satisfying the requirements of different acting forces in the ejecting process of the electrical card.
Another object of the present invention is to provide an electrical card connector which has a simplified multi-stroke ejector means for lowering the manufacturing cost thereof.
Another object of the present invention is to provide an electrical card connector of which one of the pair of symmetric and supporting surfaces cooperating with the lever can offer a longer force arm than the width half of the housing body for providing a labor-saving function in an instant when the electrical card is drawn from the connection with a plurality of contacts of the connector.
Another object of the present invention is to provide an electrical card connector of which a shortest distance formed between the pair of symmetrical supporting surfaces as being a linear contour which is parallel to a mating surface of the connector for providing the lever respectively pivoting upon the symmetrical supporting surfaces with the same radians to ensure either the electrical card being really drawn from the connection with the contacts of the connector or the electrical card being completely ejected out.